Wheel gauging apparatus



Jan. 8, 1952 CARRIGAN 2,581,630

WHEEL GAUGING APPARATUS Filed Sept. 10, 1945 4 Sheets-Sheet 1 TeAcY CAER/GAN.

Jan. 8, 1952 CARMGAN 2,581,630

WHEEL GAUGING APPARATUS Filed Sept. 10, 1945 4 Sheets-Sheet 2 TQ AcY CARE/GAN.

Jan. 8, 1952 T. CARRIGAN WHEEL GAUGING APPARATUS 4 Sheets-Sheet 3 Filed Sept. 10, 1945 a/ a i. w

T ACY CAQQ/GA/v.

III-i:- K NG P N ANGLE OASTER AND Jan. 8, 1952 1 2,581,630

WHEEL GAUGING APPARATUS Filed Sept. 10, 1945 4 Sheets-Sheet 4 Jrwvntow TeAcY CAREJGAN. V

Patented Jan. 8, 1952 UNITED STATES PATENT OFFICE 2,581,630 WHEEL GAUGING APPARATUS Tracy CarrigamLansing, Mich, assignor'to Food Machinery and Chemical Corporation, acorporation of Delaware ApplicationSeptember 10, 1945, Serial No. 615,444

8 Claims.

This invention relates to the art or measuring alignment characteristics of dirigible vehicle Wheels, and its general object is to provide an improved portable gauging apparatus for determining the camber, caster, and'kingpin inclination of such wheels It is also an object of the invention to provide an apparatus of the character referred to which is simple and light weight in construction, accurate in operation, and easily manipulated.

A further object or theinvention is to provide a wheelgauging apparatus which canbe manufactured economically, and which is of compact construction and heat in appearance.

Additional objects and advantages of the 'invention-wi1l more readily appearfrom the following description of apreferred embodiment, as illustrated in the accompanying drawings, in which:

Fig. 1 is a front elevation of a conventional dirigible wheel of an automobile showing the gauging apparatus ofthe present invention applied to the wheel in position to determine the camber and'the caster, a portion of the tire'being broken away to facilitate the disclosure;

Fig. 2 is a plan view of the structure shown in Fig. 1, with portionof tire broken away and the upper locking member of the clamp removed;

Fig. 3 is a side elevation of the structure shown in Fig. 1;

Fig. 4 is a View similar to Fig. 3 showing the apparatus applied to the wheel in position to determine the kingpin inclination;

Fig. 5 is-a plan view of the structure shown in Fig. 4, with a portion of the tire=broken=away and the upper lockingmembertof the clamp removed;

Fig. 6 is a rear elevation partly in section of the apparatus shown in Fig, 5;

Fig. 7 is an enlarged fragmentary elevation .of

one end of the cross arm of the clamp, looking at the rear face thereof;

Fig. 8 is-an enlarged vertical section taken along the line B--8of Fig. .6;

Fig. 9 is an enlarged front elevation of the upper portion of the clamp, parts being broken away, showing the locking mechanism in unlocked position;

Fig. 10 is a vertical section taken along the line HI-I0ofFig.9;

Fig. 11 is .a sectional view similar to Fig. 10 showing .the locking mechanism in flocked position, with portions broken away and otherportionsof'the structurein elevation;

Fig. 12 is a plan view of the wheel aligning gauge removed from the bracket;

Fig. 13 is a vertical longitudinal section'taken along the line i 3l3,of Fig. 12;

Fig. 14 is a vertical transverse section taken along theline I l-f4 oTF'lg. 12;

Fig. 15 is a horizontal section taken along the line] 5--l 5 of Fig. 14; and

Fig. 16 is a vertical section taken along the 1ineI'6-l6 of Fig. 15.

Referring to the drawings, and especially to Figs. 1,2 and 3, the gauging apparatus comprises a clamp generally indicated at II, a bracket l2 slidably mounted on said clamp, and a gauge 13 carried by said bracket. .As a unit these three elements are adapted to be mounted on the dirigible wheel of a vehicle, such as 'the'fron't wheel of an automobile shown at [4. By mounting the gauge i3 in proper relation to the clamp ll and then moving the wheel to certain positionsin the manner to be hereinafter described, an operator can quickly check the caster, camber, and'king pin inclination of the wheel. Theapparatus may then easily 'beremoved and applied to the opposite Wheel to determine its caster, camber and kingpininclination.

Thefront wheel l4 herein shown includes arim l5 adapted to support a tire M6, the wheel having the .usual hub mounted on a stub axle orspindle i7 pivoted on a kingpin l8 carried .by the usual structure 19 at the front end of an automobile.

The clamp H is substantially in the form of an inverted T having .acrossarm 21 from which a pair of parallel rods 22,13 project upwardly and .constitute the stem .of the T. The rods .22, 23 are spaced a suitable distance relative to each other and .are arranged equidistantly at opposite sides of .a line extending perpendicularly from the midpoint of the cross-arm 2|.

Secured to and projecting laterally from each extremity of the .cross arm 2|, is a spacer block or lug 24 which constitutes means .for-spacing the clamp H from the side of the wheel. 14. For convenience .each spacer block 24 is cylindrical and .has .a hat outer face adapted :to be positioned against the periphery of the rim I5 of the wheel. A screw stud 25 is mounted in the end of each block or lug 24, said stud being preferably formed of hardened steel and being arranged eccentric with respect to the center of the circular face of the spacer block, as shown in Fig. '7. The screw stud 25 projects outwardly from the spacer block a suitable distance so that it can engage the rim l5 in the manner to be hereinafter described. Each spacer block or lug 24 is secured to the cross arm 2| by means of a cap screw 25. By loosening the cap screws 26 the spacer block can be rotated so ,thatthe screw stud 25 can be positioned toj enjgagef either? the inside or the outside of the periphery of the rim |5. In the present instance the parts are shown positionedso that the screw studs will engage the outside of the rim l5. e

For the purpose of enabling the clamp H to be easily and quickly attached to jiaflwheel and detached therefrom, a locking device 3| is slidably mounted on the two rods 22, 23. ing device comprises a body having a lower portion 32, an upper portion 33 arranged in spaced relation to the lower-portion and connected thereto by an intermediate portion 34, which is somewhat varc'uate in form and which extends rearwardly from the front portion of the looking device, as shown in Figs. 10 and 11.

The lower .portion'32 of the locking device is formed with vertical bearing openings 35, 35, and the upper. portion 33 is formed with vertic'al'bearing'openings 31, 38. The openings 35, 3'! are arranged in vertical alignment to receive the rod22, and the openings 36, 38 are arranged in vertical alignment to receive the rods 23 (see Fig. 9). 1 f

Secured to and projecting rearwardly from the portion 34 of the body 3| is a spacer block or lug 39 which constitutesmeans' for spacing the "locking device from the side'of the wheel M; The block 39 'is substantially similar to the blocks 24 carried by thecross arm 2| and said block 39 has a hardened steel screw stud 49 mounted in the end facethereof, said screw stud being arranged eccentric with respect to the center of the circular face ofthe spacer block 39 and projecting outwardly from said spacer block a suitable'distance, as shown in Figs. 10 and 11. The spacer block 39 is secured to the portion 34 of the body of the locking device by means of'a screw 4| which is arrang'edconcentrically in said'block, the'construction and arrangement of the parts being similar tothe construction and arrangement-of the spacer blocks 24'heretofore described. The studs 25 and 40 provide means for engaging the periphery of the rim l5 of a wheel'at three widely separated points when the clamp II is mounted on the wheel in the manner shown in Fig. 3, so that the clamp can be made rigid with the wheel.

'Inte'rposed within the body 3|, in the space between the lower portion 32 and the upper por-' tion 33, is a locking plate 42, comprising a substantially T-shaped body having a cross arm 43 formed with two'spaced openings 44, adapted to loosely receive the rods 22, 23, respectively, and an arm or stem 45 arranged at right angles to the cross arm-43. The cross arm portion '43 of'the locking plate 42 overlies the portion 32 of the body 3| of the locking device, and interposed between the upper face of the cross arm 43 and the lower face of 'the upper portion 33 of the body 3| and encircling the rods 22, 23, are coiled springs 41, which normally maintain The lock- 4 the locking plate 42 in face to face relationship with the upper face of the lower portion 32 of the body 3|. Projecting downwardly from the extremity of the arm 46 of the locking plate 42, is a lug 48 having a cam surface 49 which is inclined upwardly from the lower rear edge of the lug, as shown in Fig. 11.

Rotatably mounted in aligned openings 5| formed in the lower portion 32 of the body 3| of the locking device, is an actuator shaft 52 for the locking plate 42. The shaft 52 is disposed between the rods 22, 23, being located substantially along the longitudinal center line of the body of the locking device, as shown in Fig. 9. The outer end of the actuator shaft 52 is provided with a handle 53 by which said shaft may be rotated, and near its inner end the actuatorshaft 52 is provided with a transverse slot orhrecess54 for the reception of the lug 48 when the parts are in the position shown in Fig. 10.

The construction and operation of the parts 'so far described is such that the clamp Il may be applied to the Wheel with the studs 25 positioned against the outer edge of the rim l5, and the locking device 3|, in its unlocked position, as shown in Figs. 9 and 10, is then slidablyadjusted along the rods 22, 23 to bring the stud 43 into engagement withthe outer edge of the rim I5, as shownin Figill.

The clamp, while thus positioned, is now pressed inwardly firmly against the rim I5 and while it is so held, the handle 53 of the locking device is turned so as to rotate the actuator shaft 52. The first reaction of this rotation is to cause the surface of the recess 54 of the actuator shaft to lift on the lug 48 of the locking plate 42 thereby tilting this plate relative to the rods 22, 23, as shown in Fig. 11. The openings 44, 45 in the locking plate 42 through which the rods 22, 23 extend are just large enough for the locking plate to be tilted so that it binds against the rods when the locking plate reaches the limit of this tilting'movement. The rotation of the actuator shaft 52, is continued however, with the result that the action of the surface of the recess 54 of thejactuatorshait is to slide the body of the locking device 3| downwardly on the rods 22, 23, over a short distance but with considerable force. The force of this movement is sufficient to cause the studs'25 and 40'to tightly engage the periphery of the rim, I51 As this motion is completed, the edge 53 of the actuator shaft 52 engages the inclined surface 49 of the locking plate 42. This locks the locking device 3| in'the position into which it was just moved on the rods 22, 23 which maintains the studs 25 and 45 in tight engagement with the wheel rim l5until the actuator shaft 52 is reversely. rotated to restore the looking device 3| to slidable relation with the rods 22, 23. The locking device 3| can then be slid upwardly of the rods 22, 23 to disconnect the stud 4|] from-the rim I5. The main body of the clamp H can then be lowered to disconnectthe studs 25 -from the rim l5.

Incase-a wheel is encountered in which space is not available to accommodate the studs 25 and 40 outside the rim |5, the clamp ll may be ap plied to the rim with the studs 25 and 45 contacting the interior face of the periphery of the rimLj' This is accomplished by loosening the cap screwsifi and'4l respectively, rotating the spacer blocks 24 and 39, respectively a half-turn each,

and then tightening'the cap screws. The locking ymnast device 'tlis" then s'lid-oif ofthe rods 2 2 23 inverted-,- and then replaced on these bars.

The clamp it is now ready for applicationto the rim of a wheel with thestuds 25 and 4e engaging the interior surface of that rim. The handle is then-actuated to cause the locking plate 42' to grip the rods 22, 23 and shift the locking plate upwardly forcefully to impinge the st'uds 25, ln inth'e inner surface of the rim i5 and thus unite the clamp It with the rim. The relaxing of the locking plate releases the clamp It from this position in exactly the same manner as previously described for the position in which the studs 49 are disposed outside the rim.

.As shown in Figs.-1, 2 and 6, the bracket Iii comprises abody of substantially rectangular form having a bearing boss 53 at each corner thereof, each boss having an opening bored lengthwise thereof for receiving the rods 22, 23 whereby the bracket is slidably supported by said rodsand can be moved rectilinearly thereon. In order to retain the bracket :2 in adjusted. position with respect to the rods 22, 23, the body oi the bracket is formed with a pair of openings 59 which are spaced apart a distance equal substantially to the distance between the longitudinal center lines of the rods, 22, 23. Disposed within each opening 59 is a lug 68 carried by an end portion of a leaf spring 6!, the other end of the leaf spring being secured to the body of the bracket by a screw 62 or other suitable means, as shown in Fig. 8. The leaf spring is adapted to force the nose of the lug against the surface of the adjacent rod so that the bracket is f-rictionally retained in position on the rods 22, 23 in Well known manner. Projecting outwardly from the central portion of the bracket i2, is a pivot arm 53 adapted to support the gauge it in the manner to be hereinafter described.

As shown in Figs. 12, 13, 14, and 16, the gauge i3 comprises an elongated substantially rectangular hollow housing formed of .two complementary sections, one of which is indicated at "El and will bereierred to as the front section, and the other of which is indicated at T2 and will be referred to as the rear section.

The housing sections H, H are assembled to-- gether with their marginal edges face to' face, and said sections are held together by means of screws "E3, or other suitable means arranged in suitable spaced-relation around the periphery of the gauge body.

Each of the housing sections H, 12 has-an inwardly projecting arcuate ledge at its upper end, these ledges being indicated at 14 and 15, respectively, Fig. 14. The adjacent longitudinal edges of the ledges. l4 and 15 are spaced apart, as shown, to provide a slot 16 which extends across the top of the housing, the ends of said ledges being spaced from the end walls of the housing, as indicated at 11, "I8 inFig. 16.

As shown in Fig. 12 two sets of scales 81 and 82-, areprovided, one for use in determining. the camber, and the other for use in determining caster and king pin inclination. The camber scale 8| includes suitable graduations formed on a scale plate, which plate is adjustably secured to the arcuate ledge 15 by a pair of screw studs 83 each of which extend through a slot in the scale, Fig. 12. The slots in the scale 8| are arranged in such a manner that the scale can be adjusted to set the zero position of the scale correctly.

The scale 82 comprises an endless band or loop formed of suitably flexib1e,..ribbon"-like material which encircles two spaced? rollers 84,. suitable graduationshbeing Iormedl on! a portion of the loop, as: shownlinl Fig. 12. The rollers 84:, 35 are.- nxeuly mounted on shafts 8 E, 8 Ti respectively, said shafts being. journalled in. the front and rear housing sections ll, i2 and being-disposed transversely of the-housing, as. shown in Figs; 13:, 14, 1'5 and 16. The roller 85 is anidlernrouer'. The shaft 8fion which the roller 84 is mounted pro-'- jects a suitable distance beyond the front face N of .the'housing of the gauge and has mounted thereon a knob 88' which is conveniently located outside of the housingfor manipulation by an operator. In order to prevent the material comprising the scale 82 from slipping when the roller 84 is rotated, said roller is covered or coated with rubber or other suitable friction material, as indicated at 89, Figs; 15, 16 The friction material 89 is designed to provide a;- traction surface for the scale loop 82. The constructionand arrangement of the parts is such that the upper fiightof the loop material comprising the scale 82 rests upon the upper surface of the arcuate' top wall "It, the side edge of the scale82 being spaced" from the adjacent IOngi tud inal' side edge of the scale plate 8| above the slot T6,as shown in Fig. 114.

Mounted on top of" the body ofthe gauge is: a cover 90 provided with an inspection. opening: 9T through which the scales BI, 82 are exposed,v said cover having a depending flange formed around its periphery so that: the main body of the cover is spaced from the upper surfaces of the scales. In this way the scale 82 is freely movable when the knob 88 is operated. The cover 9b is held fixed in position by means of screws 92, Fig. 12.

Aligned bearing openings and 9B are formed in the end walls of the gauge housing at a suitable point above the center of gravity of the gauge for the reception of the gauge supporting arm 63 and. the gauge is freely journalled onthis arm so that it will automatically gravitate to verticalposition with the top of the gauge upper most at all times.

At a distance below the point in the body of the gauge I3 in which the bearing openings 95', 96' are located, additional aligned bearing openings IN, [02, are formed in the front and rearwalls respectively, of the gauge housing for a shaft I03; The shaft I 03 is disposed at right angleswith respect to the gauge supporting arm 63, as shown in Figs. 13 and 14, and said shaft provide means for supporting -a pendulum pointer I04, which is rotatably mounted on the shaft by means of ball bearings M5 The pen dulum pointer I64 comprises an upwardly projecting pointer I06 and a weighted lower end it? adapted to maintain the pendulum pointer ltd in avertical position at all times. Theupper end I05 of the pendulum pointer is located within the slot 16 for oscillatory movement therealong in proximity to the indicia on the scales Si, 32.

It is to be observed that in the illustrated embo'dim'ent of the present invention the axis of the pendulum pointer I94 is disposed at right angles with respect to the axis of the shaft 53. This arrangement of the parts isdesirable for purposes of compact construction. In order to make this arrangement of the pendulum pointer with respect to the shaft 63 possible the pendulum pointer IM is offset to clear the shaft 53, the offset being in the form of an eye l fiB-,Fi'g. 14. The area-of the eyeshould be such that the pendulum pointer I 04 is free. to swingwithinthe housing of the.gauge about the pivot provided by shaft I03 without interference by the arm 63. In this wayfreeoscillation of thegauge. on the supporting. arm 63, aswell as free oscillation of thependulum pointer I04 withinthe gauge housing is provided for.. In order to checkcaster the gauge is mounted onthe wheel .in the manner shownin Figs. 1, 2 and 3. so that the shaft I03 ofthe pendulum pointer I04 is substantially parallel with respect to the. side of the wheel and the pendulum pointer IN is arranged to oscillate in a direction at right. angles with respect to the side of the wheel. With the gauge I3 mounted on the wheel in the. above manner, the. wheel is turned to. one

side of. straight ahead, a predetermined angle.

' position of the wheel, the relative position of the gauge I3 is also changed, since the plane of the wheel due to the caster is tilted to a different position, and the angular position of the gauge supporting arm .03 is likewise given a different tilt. Consequently since the gauge I3 is 3 supported. lengthwise on the arm 63, the top of the gauge I3 will be disposed in a different angular position, and since the position of the pendulum pointer I remains unchanged, the scale 82 will indicate the difference between the two positions of the gauge and this difference is the caster inclination of the king pin in degrees Camber can be determined with thegauge I3 mounted on the wheel in the same position as it is mounted on the wheel during the caster tests. The first step in making a camber check is to set the wheel truly straight ahead. The amount of camber is determined by noting the position of the pendulum pointer I06 with respect to the camber scale BI which is fixedly secured to the top of the gauge I3. Since the gauge I3 is carried by the clamp I I in a predetermined position with respect to the wheel I4 and since the wheel is inclined outward at the top relative to a vertical line, the top of the gauge I3 having the caman angle with respect to the vertically disposed pendulum I04. Consequently, it is only necessary to note the degrees indicated by the pointer I06 on the scale BI, in order to determine the camber inclination. 7

When the bracket I2 is mounted on the clamp I I with the rods 22, 23 extending through all four iii bosses 50, the bracket will be held rigid with shown in Figs. 4, 5 and 6. In this latter position the bracket I2 can be rotated about the pivot provided by the rod to dispose the gauge in the desired position.

With the bracket I2 mounted on a single rod, either rod 22 or rod 23, the gauge I3 is mounted on the gauge supporting arm 03. The gauge and the bracket are then swung about the pivot provided by the pivotal connection of the bracket on the rod to a position in which the longitudinal center line of the housing of the gauge is disposed substantially parallel with the side of the wheel (see Fig. 5). In this position of the gauge the pendulum pointer I04 will swing in a direction parallel to the plane of the wheel.

With the gauge I3 mounted on the wheel in the above manner, the wheel is turned out to a position at a predetermined angle from straight ahead. The wheel is then looked against rotation in any suitable manner, so that it will not turn on the spindle while the test is being made. The knob is then operated to move scale 82 so that the zero position on said scale aligns with the pointer I06 of the pendulum I04.

The wheel is then turned inwardly to an angular position from straight ahead corresponding to the first angular position at which the wheel was set. The angular position of the gauge supporting arm 63 will be given a different tilt-due to the king pin inclination, and consequently, since the body of the gauge I3 is supported r lengthwise on the arm 63, the top of the gauge I3 will be disposed in a different angular position, and since the position of the pointer I08 remains unchanged, the scale 02 will indicate the difference between the two positions of the gauge and this difference is the king pin inclination in degrees.

Having now described my invention and in What manner the same is used, what I claim as new and desire to protect by Letters Patent is:

1. A device for measuring alignment characteristics of dirigible vehicle wheels comprising, a hollow body having aligned bores in opposing walls thereof, a clamp adapted to be rigidly secured to a wheel, a bracket carried by said clamp, an arm projecting outwardly from said bracket and extending through the aligned bores of said housing so that the latter is suspended from said arm for swinging movements in a plane, a graduated scale adjustably mounted on the upper portion of the hollow body, a pendulum arranged within said hollow body for swinging transversely thereof and having a pointer provided with an eye encircling said arm so as to permit unobstructed swinging movements of the 3 pointer within said body for cooperation with her scale SI mounted thereon is also disposed at said scale, means in said housing for pivotally connecting said pendulum thereto at a point substantially below said arm to thereby cause said housing to tend toward a vertical attitude. the length of the pointer being substantially greater than the length of the pendulum. below said pivotal connecting means whereby the move-' ments of said pointer relative to said scale are amplified in proportion to swinging movements of said pendulum within the body responsive to; variations in the tilted attitude of said wheeli during testing thereof, and means for adjusting.

the position of said scale to register its zero indication with the position of said pointer when the wheel is disposed in a predetermined position- 2. A device for measuring alignment characteristics of dirigible vehicle .wheels comprising, a

member having a hollow body, means for attaching said member to a wheel in pendent position comprising an arm carried by said wheel and extending through the body of said member at a point above the center of gravity of the member whereby themember is free to swing in a substantially vertical plane at right angles to the longitudinal center line of said arm, anindicating scale on the upp'erportion-of said member, and a weighted pointer pivotallymounted within the hollow *body of said member attagpointebeneath said arm,.-said pointer extending i-upwardly within the body-of said member and having an eye formed therein through whichjthe arm extends to :permit rfree swinging movements of said pointer through a path intersecting the longitudinal center lineof saidiarm.

3. A 'device for measuring ,alignment characteristics of dirigible vehicle wheels comprising a hollow body adaptedto be applied to a wheel, a pendulum pivotally mounted within said bodyzfor swinging movements about an :axis disposed in the lower region of said body, said pendulum having a pointer at the upper end thereof disposed in proximity to the top of the body, a scale comprising a loop of ribbon-like material having graduations thereon, said scale being disposed in the upper portion of the body in proximity to said pointer, a pair of spaced rollers mounted on shafts rotatably mounted in the body for supporting the loop, and a knob mounted on one of said shafts for turning the shaft to effect lengthwise movement of the loop whereby the relative position of the graduations on the scale with respect to said pointer can be adjusted.

4. A device for measuring alignment characteristics of dirigible vehicle wheels comprising, a gauge having a hollow body, means for attaching said gauge to the wheel in pendent position, a pendulum pivotally mounted within said gauge body for swinging movements transversely of the body and being connected to said body sufiiciently below the point of attachment thereof to said wheel for maintaining said body in a vertical position, said pendulum extending upwardly within said body and having a pointer at the upper end thereof disposed in proximity to the top of the body the effective length of the pendulum below the pivotal axis thereof being substantially less than the distance from said axis to the upper end of the pointer so as to amplify the movement of the pointer adjacent the top of said body relative to the movement of said pendulum responsive to tilting of said wheel, a scale in the form of an endless piece of ribbon-like material having graduations thereon disposed in proximity to said pointer, a pair of rollers mounted on shafts arranged transversely in the upper portion of the body and spaced apart for supporting the scale, and a knob mounted on one of said shafts by which the roller on the shaft is adapted to be rotated to move the scale transversely of the hollow body of said gauge whereby the scale can be adjusted to indicate the alignment characteristics of the wheel.

5. A device for measuring alignment characteristics of a dirigible vehicle wheel comprising, a hollow housing formed of two complementary sections, each section having an inwardly projecting arcuate ledge at its upper end, the adjacent longitudinal edges of said ledges being spaced apart to provide a slot which extends across the top of the housing, the ends of said ledges being spaced from the end walls of the housing, a scale comprising an endless loop of ribbon-like material encircling one of said ledges with the upper stretch of said loop resting upon the upper surface of the same and formed with graduations thereon in proximity to the adjacent said slot, a pair of spaced rollers mounted on shafts rotatably mounted in the housing for supporting the ends of the scale loop, manually 1 0 operable means iixed "to one of said. shafts for turning the shaft to effect lengthwise movement of the scale loop whereby the relative position of the graduations on "the scale canfbe adjusted, and 'a pendulum *pivotally mounted within said housing for swinging movement about an axis disposed in thelower region thereof and having a pointer disposed in said slot for cooperating with said graduated scales to"'indic'ate alignment characteristics of the wheel.

6. A device for measuring alignment characteristics of a dirigible vehicle wheel comprising, a :hollow housing, a ledge projecting-inwardly from one side wall at the upperportionuof said housing, said ledge being spaced from the opposite side wall of the housing to provide a slot which extends transversely of the upper portion thereof, the ends of said ledge being spaced from the end walls of the housing, a graduated scale comprising an endless ioop of material encircling the said ledge with the upper flight of the loop resting upon the upper surface of said ledge, means within the housing for supporting said loop with its upper reach disposed on said ledge, means for effecting movement of said loop whereby the graduations thereon can be shifted transversely along said ledge, and a pendulum pivotally mounted within said housing for swinging movement about an axis disposed in the lower region thereof and having a pointer disposed in said slot in proximity to the graduations on said scale.

'7. A device for measuring alignment characteristics of dirigible vehicle wheels comprising, a bracket adapted to be detachably clamped to a wheel, an arm projecting outwardly from said bracket, a hollow body having aligned bores in opposing walls adapted pivotally to receive said arm therein whereby said body is suspended from said arm in a pendent position, a graduated scale on the upper portion of said hollow body, a pendulum within said body having a pointer cooperating with said scale and provided with an offset portion for clearing said arm during movement of said pointer within said body, and means for pivotally mounting said pendulum within said body at a point below said arm for tending to maintain said hollow body in a vertical position, said pivotal mounting means being spaced from said scale by a distance substantially greater than the length of said pendulum below said pivotal pendulum mounting means for effecting movements of said pointer therealong in amplified proportion to the movement of said pendulum responsive to tilting of said wheel thereby permitting enlargement of the spacing between the graduations of the scale.

8. A gauge for measuring the alignment characteristics of a dirigible vehicle wheel comprising, a shaft attached to said wheel so as to extend coaxially outwardly therefrom, a hollow housing having bores in opposite walls aligned to receive said shaft for effecting swinging movement of said housing, an indicating scale on the upper portion of said housing, a pointer pivotally mounted within said housing for swinging movement in a plane parallel with the disposition of said scale for cooperation therewith and having a weighted portion substantially below said shaft for balancing said housing in a pendent position thereon and to maintain said pointer upright, said pointer having an offset portion in the region of said shaft for permitting unobstructed movement of said pointer within said. housing, and pivotal mounting means disposed in the lower region of said housing for pivotally supporting said pointer, said pivotal mounting means being located a substantial distance further from said scale than from the weighted lower end of said pointer to efiect movement of the upper end of said pointer along the scale in greater proportion than the movement of the weighted lower portion of said pointer responsive to tilting of said wheel. I

TRACY CARRIGAN.

REFERENCES CITED The following references are of record in the file of this patent:

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